Vulnerability in github.com/enchant97/note-mark/backend (CVE-2026-44523)
Summary
Vulnerability in github.com/enchant97/note-mark/backend (CVE-2026-44523). Confidential information can be exposed externally. Exploitable via JWT_SECRET. Mitigation: upgrade to 0.0.0-20260501152247-18b587758667 or later.
Original description
The description as published by the source.
Summary
No minimum length or entropy is enforced on the JWT_SECRET configuration value. The application accepts any base64-decodable secret regardless of size, including secrets as short as 1 byte.
HS256 secrets below 32 bytes are brute-forceable offline, allowing attackers to recover the signing key and forge valid JWTs for arbitrary users.
Impact
An attacker who captures a single valid JWT (e.g, from cookies, logs, or network traffic) can:
> Crack the signing secret offline using brute-force or wordlist attacks
> Forge valid JWTs for any user ID (including administrators)
> Authenticate without knowing any credentials
This results in full account takeover across the entire application with no server-side detection or rate limiting possible.
Details
In backend/config/utils.go, the Base64Decoded.UnmarshalText function decodes the JWT secret but does not validate its length or entropy.
In backend/core/auth.go, JWT tokens are signed using HS256 without enforcing minimum key size requirements.
According to RFC 7518 Section 3.2, HS256 keys must be at least 256 bits (32 bytes). Libraries such as PyJWT explicitly warn against shorter keys, but note-mark performs no such validation.
PoC
1- Deploy note-mark with a weak secret:
JWT_SECRET = base64("testsecret123456789012345")
2- Register an account and capture the Auth-Session-Token cookie
3- Crack the secret offline (example using Python):
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-44523 has been found in github.com/enchant97/note-mark/backend.
Attackers can target a specific entry point like JWT_SECRET over the network to misuse the product.
Confidential information can be exposed externally. CVSS score: 10.0/10.
What to do: upgrade github.com/enchant97/note-mark/backend to 0.0.0-20260501152247-18b587758667 or later.
If unsure, ask your IT team or search "github.com/enchant97/note-mark/backend CVE-2026-44523" on the vendor's site.
CVE-2026-44523 (github.com/enchant97/note-mark/backend) — CWE-326 / CVSS v3 10.0
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
Attack surface: JWT_SECRET / Base64Decoded.UnmarshalText
Patched: 0.0.0-20260501152247-18b587758667 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-326) exists in github.com/enchant97/note-mark/backend. Attackers reach the vulnerable code path via JWT_SECRET without authentication.
Check the vendor advisory for the affected versions of github.com/enchant97/note-mark/backend. Attack surface: JWT_SECRET / Base64Decoded.UnmarshalText.
Severity: Critical (CVSS 10.0/10). Confidential information can be exposed externally.
Update to 0.0.0-20260501152247-18b587758667.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'github.com/enchant97/note-mark/backend' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'github.com/enchant97/note-mark/backend' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
github.com/enchant97/note-mark/backendを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade github.com/enchant97/note-mark/backend to 0.0.0-20260501152247-18b587758667ステージング環境で 0.0.0-20260501152247-18b587758667 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- advisory nvd.nist.gov
- package github.com
- web github.com
- web github.com
- web github.com
- web github.com